pandoc/Text/XML/Light/Proc.hs
fiddlosopher 0c6dd105b7 Added code for xml library (Text.XML.Light) to source tree,
since there is currently no debian package.  Removed
dependency on xml library.  Added license to debian/copyright.


git-svn-id: https://pandoc.googlecode.com/svn/trunk@1351 788f1e2b-df1e-0410-8736-df70ead52e1b
2008-08-01 00:45:07 +00:00

103 lines
4 KiB
Haskell

--------------------------------------------------------------------
-- |
-- Module : Text.XML.Light.Proc
-- Copyright : (c) Galois, Inc. 2007
-- License : BSD3
--
-- Maintainer: Iavor S. Diatchki <diatchki@galois.com>
-- Stability : provisional
-- Portability:
--
--------------------------------------------------------------------
module Text.XML.Light.Proc where
import Text.XML.Light.Types
import Data.Maybe(listToMaybe)
import Data.List(find)
-- | Get the text value of an XML element. This function
-- ignores non-text elements, and concatenates all text elements.
strContent :: Element -> String
strContent e = concatMap cdData $ onlyText $ elContent e
-- | Select only the elements from a list of XML content.
onlyElems :: [Content] -> [Element]
onlyElems xs = [ x | Elem x <- xs ]
-- | Select only the elements from a parent.
elChildren :: Element -> [Element]
elChildren e = [ x | Elem x <- elContent e ]
-- | Select only the text from a list of XML content.
onlyText :: [Content] -> [CData]
onlyText xs = [ x | Text x <- xs ]
-- | Find all immediate children with the given name.
findChildren :: QName -> Element -> [Element]
findChildren q e = filterChildren ((q ==) . elName) e
-- | Filter all immediate children wrt a given predicate.
filterChildren :: (Element -> Bool) -> Element -> [Element]
filterChildren p e = filter p (onlyElems (elContent e))
-- | Filter all immediate children wrt a given predicate over their names.
filterChildrenName :: (QName -> Bool) -> Element -> [Element]
filterChildrenName p e = filter (p.elName) (onlyElems (elContent e))
-- | Find an immediate child with the given name.
findChild :: QName -> Element -> Maybe Element
findChild q e = listToMaybe (findChildren q e)
-- | Find an immediate child with the given name.
filterChild :: (Element -> Bool) -> Element -> Maybe Element
filterChild p e = listToMaybe (filterChildren p e)
-- | Find an immediate child with name matching a predicate.
filterChildName :: (QName -> Bool) -> Element -> Maybe Element
filterChildName p e = listToMaybe (filterChildrenName p e)
-- | Find the left-most occurrence of an element matching given name.
findElement :: QName -> Element -> Maybe Element
findElement q e = listToMaybe (findElements q e)
-- | Filter the left-most occurrence of an element wrt. given predicate.
filterElement :: (Element -> Bool) -> Element -> Maybe Element
filterElement p e = listToMaybe (filterElements p e)
-- | Filter the left-most occurrence of an element wrt. given predicate.
filterElementName :: (QName -> Bool) -> Element -> Maybe Element
filterElementName p e = listToMaybe (filterElementsName p e)
-- | Find all non-nested occurances of an element.
-- (i.e., once we have found an element, we do not search
-- for more occurances among the element's children).
findElements :: QName -> Element -> [Element]
findElements qn e = filterElementsName (qn==) e
-- | Find all non-nested occurrences of an element wrt. given predicate.
-- (i.e., once we have found an element, we do not search
-- for more occurances among the element's children).
filterElements :: (Element -> Bool) -> Element -> [Element]
filterElements p e
| p e = [e]
| otherwise = concatMap (filterElements p) $ onlyElems $ elContent e
-- | Find all non-nested occurences of an element wrt a predicate over element names.
-- (i.e., once we have found an element, we do not search
-- for more occurances among the element's children).
filterElementsName :: (QName -> Bool) -> Element -> [Element]
filterElementsName p e = filterElements (p.elName) e
-- | Lookup the value of an attribute.
findAttr :: QName -> Element -> Maybe String
findAttr x e = attrVal `fmap` find ((x ==) . attrKey) (elAttribs e)
-- | Lookup attribute name from list.
lookupAttr :: QName -> [Attr] -> Maybe String
lookupAttr x as = attrVal `fmap` find ((x ==) . attrKey) as